Loud? Look at the six-bladed engines of Dornier 328 and compare them with the engines of a Saab 340 (4-bladed?). In fact, Dornier's 328 came around 10 years after Saab's 340. It is the fastest (335 knots at cuise-speed) AND the most quietest aircraft in its class.

The Dornier 328 prop is a fairly comfortable aircraft. It is not loud...try riding a DC9/M80 with an engine a foot from your head...now, that's loud.

The airlines didn't buy the D328 because of several reasons....the bigest reasons are:

1) bad timing...I believe it entered service in the early to mid 1990s....this was about the same time as the introduction of regional jets.
2) it is more advanced than other similar turboprops...you would think this would be a good thing, but it meant higher aquizition costs than similar sized aircraft.
3) Most commuter lines already had a lot of Dash-8, Saab 340, EMB-120, and J-41 types...they all are around 30-35 seats...most airlines didn't want to add a completly new aircraft type to their fleet.

I hate the 328 jet, I flew on it from MKE to IND and it was terrible..it smoked pretty bad ( I was in the last row) from the engines and it was a horrible ride...I would rather have flown on a NWA CRJ...very nice AC.

I was on Team Lufthansa´s 328 prop - and it´s just terrible - a cramped, lousy loud aircraft with only one overhead bin.
Gimme a Dash 8 anytime. Even F50s or ATRs are better than that Dornier (all from the the very subjective point of view of a passenger).